You are here:
4-Acetoxyphenol as a substrate for acetylcholinesterase-based sensor and its application for As(III) determination
Citation:
Li, T., E. Sahle-Demessie, J. Berberich, AND E. Varughese. 4-Acetoxyphenol as a substrate for acetylcholinesterase-based sensor and its application for As(III) determination. To be Presented at 256th ACS National Meeting, Boston, MA, August 19 - 23, 2018.
Impact/Purpose:
This work demonstrated using the novel substrate for amperometric assay of acetylcholine esterase (AchE), thereby eliminated the issues caused by the common substrate acetylthiocholine iodide. This assay was used in AchE sensor development and protocol development for As(III) determination. A new protocol was developed based on the inhibition mechanism. The assay was robust and free from common interferants such as Cu2+, humic acid, etc. The sensor was stable at room temperature for 150 days, therefore enough for practical applications.
Description:
4-Acetoxyphenol (CAS 3233-32-7) was used as the substrate for electrochemical assay of acetylcholinesterase (AchE). The enzyme activity was reported as the electrical current generated by anodic oxidation of hydroquinone, the product from esterase-catalyzed hydrolysis of 4-Acetoxyphenol. This reaction sequence was applied to As3+ determination with an amperometric biosensor, which was prepared by immobilizing AchE on a carbon screen-printed electrode. A protocol was developed based on quasi-irreversible inhibition of AchE by As3+. The concentration of As3+ correlated to the decrease of anodic current in a logarithm relationship. The analysis had a dynamic range of 2-500 M As3+ with maximum current reduction of 70% and a lower detection limit of 2.2 M. The AchE sensor had a shelf life for at least 150 days at 22 ± 2 °C. The analysis was free from the interference by Cu2+, a reversible inhibitor to AchE and interferrent in arsenic determination by stripping voltammetry